Phlips 50's AC/DC sets - common failure faults

I've seen this fault on several differing Philips AC/DC models and that is the radio turns on, you hear mains hum but within minutes a large resistor in the power section starts smoking/turning black. I think it's due to an associated ht smoothing electrolytic capacitor going leaky to earth but until now have not had to track it down.

Does this ring a bell with anyone???